What i do in your case is to extend CListView but this is because I create my own widgets; there is another option and easier one: why dont you just include a search field before the rendering of the widget?
<h1>Job Postings</h1>
<?php // HERE INCLUDE THE SEARCH FORM?>
<?php $this->widget('zii.widgets.CListView', array(
'dataProvider'=>$dataProvider,
'itemView'=>'_jobview',
)); ?>
Then it is just a matter to point the action to the controller/action that renders the list and have the appropriate search function that will filter upon the POST parameters.